calling system call in arm from user space

Hi, I have written a system call and build it with kernel for Arm architecture. However, I'm confused to use it to call it from the user space. As it is in x86, where we can simply call by using sycall() function and the return value is returned by the syscal() itself. In Arm, I tried to write an assembly language program and was able to call the system call using the assembly code but what I'm confused is how to call this function using C program. I tried using inline assembly but it didn't work. Further, if I can implement it using inline assembly then return value will be in r0 and how can I move this value to the user variable. Thanking you in advance. -- Niroj Pokhrel Software Engineer, Samsung India Software Operations